I am currently on my third (or maybe fourth) iPhone, and every one was replaced for multiple reasons. The headphone jacks are only good for a few thousand inse

I am currently on my third (or maybe fourth) iPhone, and every one was replaced for multiple reasons. The headphone jacks are only good for a few thousand insertions, the batteries get worn out, the internal components start to fail, and the buttons get mushy/broken. In addition to this, sometimes people drop them, and the screen cracks. The processors, ram, and solid state memory get out-of date, and make the product feel 'slower' and less pleasant to use than newer devices. In this environment, is it worth it to make spare parts and replaceable components? Which components would you make re-usable? On one corner of the desk that I am currently using, there sits an old aluminum 13.3" Macbook with a replaceable battery. I never replaced the battery because the laptop got dinged up, old, and slow, so the effort and resources that went into making the battery replaceable were wasted. Getting rid of 'serviceability' is often worth it.